Area Forecast Discussion
Issued by NWS Sterling, VA

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FXUS61 KLWX 200032
AFDLWX

Area Forecast Discussion
National Weather Service Baltimore MD/Washington DC
832 PM EDT Tue Sep 19 2017

.SYNOPSIS...
A ridge of high pressure will remain over the eastern United
States through early next week. Meanwhile, Hurricane Jose is
expected to track north off the Mid Atlantic coast through
Wednesday. Refer to the National Hurricane Center`s website
hurricanes.gov for the latest on Jose.

&&

.NEAR TERM /UNTIL 7 AM WEDNESDAY MORNING/...
A ridge of high pressure remains overhead this evening as
Hurricane Jose gradually moves northeastward offshore of the
Mid-Atlantic coastline. Western extent of the cloud shield from
Jose reaches to about the I-95 corridor this evening, and that
should progress eastward during the overnight hours. A few rain
showers in the far outer band also remain near the Chesapeake,
but those too should diminish.

With mostly clear skies and diminishing winds, patchy fog will
likely develop again tonight into early Wednesday morning,
mainly west of the metros. The pressure gradient from Jose
should keep enough wind in the boundary layer to prevent fog
from developing in points east.

Lows overnight will range from the upper 50s to upper 60s,
locally 70F in the urban centers.

&&

.SHORT TERM /7 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
An upper-level ridge will remain over the area...but a weak
disturbance will approach from the west. A northwest flow behind
Jose will allow for sunshine and it will be unseasonably warm
for this time of year due to subsidence associated with the
upper-level ridge. Max temps will be in the mid to upper 80s
across most locations. A few popup showers are possible later
Wednesday afternoon and evening across the Potomac Highlands
into central Virginia where there will be a little instability
closer to the weak upper- level disturbance. However...coverage
will be isolated to widely scattered due to the lack of a strong
lifting mechanism.

High pressure both at the surface and aloft will continue to
build overhead Wednesday night through Thursday night. Dry warm
conditions are expected during this time. Areas of fog are
likely during the overnight and morning hours.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
Mainly dry conditions expected in the long term period as upper
level ridge/surface high pressure continues over our area Friday
into Tuesday. Some showers over the ridges cannot be ruled out,
but looking dry over most of our CWA. High temperatures will be
in the mid 80s, around 10 degrees higher than normal. Remnants
of Jose might be lingering off of the Mid- Atlantic/New England
coast, away from us, and Maria could be somewhere in the west
Atlantic, but it is too early to tell. Check out the National
Hurricane Center`s website: hurricanes.gov, for additional
information in both Jose and Maria.

&&

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
VFR conditions are expected through the remainder of the
evening. Patchy fog will then develop overnight into Wednesday
morning, with greatest risk for IFR at CHO and MRB. Little
impact expected at other sites.

High pressure will remain over the terminals for later Wednesday
through Thursday night. Areas of fog are possible during the
overnight and morning hours.

VFR conditions expected Friday into Sunday with high pressure
over our area.

&&

.MARINE...
Jose will continue to move north well offshore, moving away
from the area tonight through Wednesday. Breezy conditions with
gusts around 20 to 25 knots have occurred this evening...with
the strongest winds over the southern Maryland Chesapeake Bay
and lower Tidal Potomac. Winds will remain near SCA criteria for
portions of the waters into Wednesday morning. Therefore the
Small Craft Advisory remains in effect for tonight into
Wednesday across the middle portion of the Bay and the lower
Tidal Potomac River as north to northwest winds channel.

Northwest winds will continue Wednesday afternoon. A few gusts
around 20 knots cannot be ruled out...but latest forecast has
gusts capped at 15 knots due to a weaker gradient as Jose moves
away. High pressure will build overhead for Wednesday night
through Thursday night.

No small craft advisory expected between Friday and Sunday due
to low wind speeds over our area.

&&

.TIDES/COASTAL FLOODING...
A Coastal Flood Advisory remains in effect for Straits Point in
St. Marys county through tonight, and will likely need to be
extended. Anomalies elsewhere have risen markedly over the past
couple of hours as northerly winds abate, so Coastal Flood
Advisories may be needed beginning late tonight into Wednesday
and Thursday. Moderate flooding cannot be ruled out at Straits
Point Wednesday into Thursday as well.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...None.
MD...Coastal Flood Advisory until 6 AM EDT Wednesday for MDZ017.
VA...None.
WV...None.
MARINE...Small Craft Advisory until 6 AM EDT Wednesday for ANZ532-533-
     540-541.
     Small Craft Advisory until 11 AM EDT Wednesday for ANZ534-537-
     543.

&&

$$
SYNOPSIS...BJL
NEAR TERM...BJL/MM
SHORT TERM...BJL
LONG TERM...IMR
AVIATION...BJL/MM/IMR
MARINE...BJL/MM/IMR
TIDES/COASTAL FLOODING...BJL/MM



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